1. Field of the Invention
This invention relates to a testing apparatus and, in particular, to an attachment for an apparatus for testing the frictional forces between two materials.
2. Background Art
Conventional clutch plates are composite materials formed by adhering a friction material to a steel plate. For purposes of warranty protection, among other reasons, manufacturers must be able to test and evaluate the durability and life-span of the clutch plates. Therefore, manufacturers must be able to test and measure the friction characteristics of the clutch plates. Further, when a system fails after use, the aged clutch plate must be tested and evaluated in order to determine the reason for failure.
A number of testing apparatuses have been proposed to test the friction and/or traction forces between two or more materials in rolling or sliding contact with each other. One such an apparatus is disclosed in U.S. Pat. No. 6,167,745, hereby incorporated by reference in its entirety. Such a device is designed to measure the rolling traction and/or friction between a friction material (or friction surface) and a second friction surface. Devices are also known to test and measure the friction between two steel components. In order to test the friction characteristics of composite materials such as clutch plates, a portion of the friction material is typically tested before the material is adhered to the steel plate. This testing process neglects the fact that the later-performed adhesion of the friction material to the steel plate affects the friction properties of the friction materials. Further, failure testing of aged clutch plates is not possible with currently known devices, because the friction material cannot be tested while attached to the steel plate in existing devices.
There exists a need for a testing device which can test an actual clutch or gear piece and give an accurate measurement of the friction properties of composite materials.